Conventional catalyst preparation techniques or thermal plasma techniques are high temperature processes which are energy intensive. Conventional high temperature calcinations and reduction may have disadvantages including, but not necessarily limited to, decreased surface area, loss of active species, use of large amounts of energy, lengthy process time, etc.
Plasmas are conductive assemblies of charged particles, neutral particles and fields that exhibit collective effects. A plasma is a collection of free charged particles moving in random directions that is, on the average, electrically neutral. Plasmas carry electrical currents and generate magnetic fields. Thermal plasmas are equilibrium plasmas and include technologies such as plasma jet, DC corona torch, plasma arc, etc. Non-thermal plasmas are non-equilibrium plasmas and may include glow discharge, radio frequency (RF), microwave technologies and the like. Thermal plasmas are typified by high electron and gas temperatures and high pressures of atmospheric or higher, whereas non-thermal plasmas have high electron temperatures, but relatively low gas temperatures and reduced pressure (<1 atm; <0.1 MPa) in most cases.
Non-thermal plasma techniques are either high pressure processes or not as flexible in general as RF non-thermal plasma in terms of gas and flow requirements for plasma generation, uniformity, pulsed or continuous wave options, duty cycle combinations, etc.
Thus, it would be desirable if a way were discovered to improve the activity, stability and/or selectivity of catalysts using a relatively less energy intensive and more versatile processes.